The present disclosure relates generally to an apparatus, system and method for magnetorheological clutch diagnostics, and particularly to a controller for monitoring and diagnosing the coil temperature of a magnetorheological (MR) clutch connected to a power steering pump of a vehicle.
Power steering systems are used in vehicles such as motor vehicles to assist a driver in steering the vehicle. In power steering systems of a hydraulic type, an engine driven hydraulic power steering pump is used for generating pressurized fluid that is coupled to a hydraulic steering gear of the vehicle. Since the traditional power steering pump is driven directly by the engine, the engine-determines the speed of the pump, and the pump operates continuously as long as the engine is running, resulting in continuous losses due to constant circulation of the hydraulic fluid through the steering gear. Also, the pump needs to provide the required flow and pressure for the worst case engine speed, which could be near idle or under static steering conditions, which contributes to additional losses due to under-utilized pump energy, and at higher engine speeds a much higher pump flow results, which contributes to further losses due to the use of an overpowered pump.
In an effort to address these losses and provide for more efficiency in the operation of the vehicle, a MR clutch coupled to a hydraulic power steering pump has been considered, which would provide for different pump operating conditions as a function of the vehicle dynamics. However, to provide for a durable and reliable powering steering system utilizing a MR clutch, it is desirable to monitor and diagnose operating conditions at the MR clutch, such as the temperature of the MR clutch coil for example. Accordingly, there is a need in the art for an apparatus and method for monitoring and diagnosing the coil temperature of a MR clutch coupled to a hydraulic power steering pump.